Glutamate receptors, particularly AMPA receptors, in the nucleus of the solitary tract (NTS) are the 3rimary mechanism for synaptic transmission between primary afferents and second-order neurons. Thus, an understanding of glutamate receptors in NTS is vital to understanding autonomic reflexes. In our previous studies of AMPA receptors we made a surprising discovery: the number of GluR1 receptor subunits significantly increases in NTS following the development of hypertension. This finding is particularly intriguing since GluR1 is found in dendritic spines, which are widely associated with synaptic plasticity in the brain. Our hypothesis is that structural remodeling in NTS neurons during hypertension leads to functional changes in individual NTS neurons that in turn contribute to alterations in the baroreceptor reflex pathway, such as central baroreflex resetting. These structural changes are found in regions of NTS that contain baroreceptive afferents and second-order neurons, but we do not know which NTS neurons contain GluRI. In the present experiments we will use a multidisciplinary approach to: (1) determine which population(s) of NTS neurons contain GluR1; (2) examine the structural and functional changes in NTS neurons following the development of hypertension; and (3) address the functional relationship between this structural neuronal change and blood pressure. The combined efforts of the Aicher and Andresen laboratories bring together expertise in anatomical and physiological techniques. This collaborative project provides a unique opportunity to directly address structural and physiological questions regarding NTS neuronal function in both the normal and hypertensive states. [unreadable] [unreadable]